New forage legume suited for livestock, wildlife

Rio Verde lablab, a recently released forage legume by the Texas Agricultural Experiment Station, could provide some relief to nitrogen fertilizer cost-shock.
Not only does it not require nitrogen fertilizer

Source: Texas A&M University | Sep 04, 2007

Rio Verde lablab, a recently released forage legume by the Texas Agricultural Experiment Station, could provide some relief to nitrogen fertilizer cost-shock.

Not only does it not require nitrogen fertilizer, Rio Verde lablab is found palatable by both cattle and wildlife, says its developer, Ray Smith, Experiment Station plant breeder based at Overton, TX.

Many of today’s highly productive, improved pasture grasses require large amounts of nitrogen, Smith said. However, Rio Verde, as do other legumes, fixes nitrogen from the atmosphere.

Forage legumes have a symbiotic relationship with rhizobium bacteria that live in small nodules on the plant’s roots. They take nitrogen gas in the air and convert it into a form of nitrogen that plants can use.

Smith envisions several production niches for Rio Verde. It could be incorporated as a component of wildlife food plots, as livestock grazing, as a hay crop, or as a green manure crop. A green manure crop is one not harvested, but tilled into the soil to improve fertility.

Prior to Rio Verde’s release, seed for all other lablab varieties was grown in Australia, Smith said. This was because other varieties were too late in maturing to produce a seed crop in Texas before being killed by the first frost.

The forage production and nutritive value potential of Rio Verde is about the same as iron and clay cowpeas at about 25 percent, Smith says. “Compared to bermudagrass, it’s generally going be higher in protein.”

But while cattle don’t like cowpeas, they find lablab forage highly palatable. White-tailed deer, which can be picky eaters, will also readily browse lablab, making it a good, low-management crop for supplemental feed in wildlife plots.

With adequate soil moisture, the legume can be planted from May through July, Smith says. It will start flowering in late August but will remain productive until the first hard frost. For summer forage and hay programs, Smith recommended planting from 30 to 50 pounds per acre. If planting for wildlife food plots, 25 pounds of seed per acre is sufficient.

Use a drill to place seed about 1 to 1.5 inches deep. An alternative planting method is to broadcast seed on disked seed bed and follow with a light disking to cover. Use care to not cover the seed more than about 1.5 inches deep.

Rio Verde tolerates acidic soils reasonably well, Smith says. “We’ve grown here in soils down to about pH 5.5 with good results. It’s not something that will take extreme acidity, but it is better at moderate levels of acidity than other crops.”

Current prices for Rio Verde seed are about $4.50 a pound. The seed is available from Turner Seed in Breckenridge. The seed company’s phone number is 800-722-8616.